As the integrated circuit industry has been developed according to Moore's law, feature sizes of CMOS devices are continuously scaled down, planar bulk silicon CMOS structure devices are now facing severe challenges. In order to overcome these problems, various new device structures have been invented; among these new device structures, Fin Field-Effect Transistor (FinFET) has been regarded as one of the new structure devices that will most probably replace planar bulk silicon CMOS devices, and therefore is under hot research nowadays all over the world.
Most of FinFET structure devices were manufactured on SOI substrates in the early time, and the manufacturing process thereof is much simpler than processes dealing with bulk silicon substrates. However, SOI FinFETs still suffer from many shortcomings like high manufacturing cost, poor heat dissipation, floating body effects and poor compatibility with CMOS process. Particularly, the floating body effects bring about quite remarkable influence to device performances. The floating body effects mainly include: Kink effect, parasitic bipolar transistor effect, transient floating body effect, hysteresis effect, etc. The floating body effects would cause lots of problems like reduction in gain of devices, noise overshoot, instable operation of devices, and decrease in breakdown voltage of source and drain. Besides, performance of heat dissipation would be lowered in SOI FinFET devices because of the existence of BOX, which consequently causes self-heating effect; accordingly, drift mobility, threshold voltage, impact ionization, leakage current, sub-threshold slope and the like would be affected by temperature.
In order to overcome abovementioned problems and to boost application of FinFET structure devices as soon as possible, further research in said area has to be done, because this is of great significance to both application of FinFET structure devices and development of semiconductor industry.